Casing head equipment



Dec. 11, 1934- G. A. HUMASON ET AL CASING HEAD EQUIPMENT Filed Jan. 23, 1933 2' Sheets-sheaf l of closing the upper end Patented Dec. 11, 1934 UNITED STATES PATENT OFFICE CASING HEAD Granville A. Humason EQUIPMENT and Margia Manning,

6 Claims.

The invention relates to means adapted to be attached to the casing head during well drilling operations and to serve the purpose of closing the upper end of the casing about the drill stem or tubing.

The invention serves the particular purpose of the casing head around the drill stem in case of an imminent blowout during the drilling operation.

It is an object of the invention to provide an effective means for sealing about the drill stem as soon as danger of blowout appears, and

to do so quickly and expeditiously so that no blowout may occur.

We desire to provide means for thus packing about theinner pipe within the casing which will efiectively seal the space around the inner pipe and also to provide means which will allow the withdrawal of the inner pipe under the pressure of gas in the well.

It is desired to provide a plurality of devices forv the purpose stated which are interchangeable and adapted to be used either while the inner pipe is stationary in the well or alternatively to be used while the inner pipe is being withdrawn from the well.

The invention further includes the effective means for latching these devices in position quickly and in a substantial way, so that they can not be released by the pressure in the well.

The invention relates particularly to the structure of the devices making up the control apparatus, all of which will be more clearly set out and explained in the specification which follows:

In the drawings herewith, Fig. 1 is a side view, parts being broken away in vertical section, lustrating one embodiment of the invention.

Fig. 2 is a topplan view in section on the plane 22 of Fig. 1.

Fig. 3 is a similar plan view in section on the plane 3-3 of Fig. 1;

Fig. 4 is a transverse section on the plane 4-4 of Fig. 1;

Fig. 5 is a side elevation of the inner bushing shown in Fig. 1;

Fig. 6 is a side view partly in vertical section illustrating a slightly different embodiment of the invention; 7

Fig. '7 is a transverse section on, of Fig. 1; and

Fig. 8 is a broken detail of the invention taken approximately on the line 8-8 of Fig. 3.

Referring particularly to Fig. 1, there is shown a well casing 1, having at the upper end thereof a casing head 2. Said casing head is flared outthe plane 7-7 wardly toward its upper end and has a seat 3 into which pipe engaging slips may be inserted, or other similar tools maybe placed in the operation of the drilling. Adjacent the upper end the outer side is formed with a laterally extending enlargement or flange 4, which is slotted radially to provide a recess 5 within which a latch operating ring 6 is rotatably supported. Above said recess is a detachable ring 7, which is angular in cross section, as shown in the drawings, 10 and adapted to be secured in place by cap screws 8.

At spaced points around the recess 5 there is provided a plurality of latching bolts 9, shown best in Fig. 3. There are four of these latching bolts shown, each of which is formed of U-shape so as to straddle the latching ring 6 and project inwardly through the wall of the casing and en'- gage with the inner bushing 10 which will be later described. There is a pin 11 extending transversely through the legs of the latching bolts 9 and through a cam slot 12 in the latching ring 6. Said slots 12 are straight slots formed so that the sides thereof form cams which tend to act upon the pin 11 extending therethrough so that when the ring 6 is rotated it will move the latching bolts in a radial direction relative to the casing head. The latching ring 6 has eyelets or handles 13 thereon by means of which said ring may be partially rotated to operate the latching bolts 9. p

To provide a temporary seat for the sealing member the bushing 10 previously noted has been constructed. Said-bushing is a tubular member formed on its outer surface to seat within the upper end of the casing head and flt closely there- 85 in, its inner wall being also tapered downwardly to form a seat for the inner bushing 14. Ioward the lower end of the bushing 10 the outer wall is recessed at 15 to receive a packing member to seal against the inner wall of the casing head. This-packing member comprises a rubber ring 16, having a projection or tenon 17 on its upper end, fitting within a recess in the lower shoulder formed in the bushing. It is held in position therein by transverse pins 18, as shown. The

lower end ofthe packing ring 16 is also reduced in thickness and extended within a recess 19 in a metal ring 20, the lowerextremity of which comes flush, with the lower end of the bushing. There is a central cavity 21 in the rubber packing member to receive fluid from the well which may find entrance thereto through a plurality of channels or ducts 22, leading through the metal ring 20 to the'inner cavity 21. Thus fluid fromthe well under pressure will be confined within the cavity 20 and tend to expand the rubber packing member to form a more rigid seal with the casing head.

There is an annular recess or groove 23 formed in the outer face of the bushing 10 to receive the latching bolts 9 on the casing head. Toward the upper end of the bushing 10 is an annular groove or recess 25 to receive a latching ring 26, operating latching bolts 27, extending through the walls of the bushing and formed in all respects like the latching ring 6 andbolts 9, previously described. This latching ring and bolts are held in position by a clamping ring 7' similar to the ring 7 previously described.

This bushing is intended to be placed in position as shown in Fig. 1 while thedrilling is proceeding. The drill stem illustrated at 28 with the drill on the lower end thereof will extend down through the bushing 10 and may be rotated as the well is drilled. When the drill is removed the bushing 10 may be raised upwardly by the drill as it is withdrawn so that access may be had thereto. However, when the drill is operating and danger from a blowout occurs, the inner bushing 14 may be seated quickly in position to entirely seal around the drill stem 28. This inner bushing 14 is split longitudinally so that it may be opened and fitted around the drill stem with the drill stem in position. As will be seen from Fig.

2, the bushing 14 is hinged at 29 so that the two halves may swing open on the plane of the hinge. One-half of the bushing has a tongue 30, which may be engaged within a recess 31 in the other half and a latch pin 32 may then be dropped down through the tongue 30 to lock the bushing in position around the drill stem. This latching pin 32 is shown in Fig. 1 as having a head 33 thereon engaged by a compression spring 34, which tends to hold the latch pin depressed in looking posi tion. There is a laterally extending handle 35 fitting through a slot in the side wall of the bushing 14, by means of which the latch may be raised and disconnected.

The outer surface of the bushing 14 fits within the inner seat within the bushing 10, and engages against the tapered shoulder 36.

The lower end of the bushing 14 is provided with a packing member 37 connected to the upper end of the bushing and to a lower metal ring 38 substantially of the same construction as is the packing member 16 and ring 20. There is a passage 39 for fluid up into the central cavity 40 in the packing member. While the upper end of the bushing 14 is latched together, as stated, the lower end of the bushing may be also latched before the bushing is dropped into sealing position. This is done by means of a sliding ring 41, which is split transversely into two parts. It is mortised into a recess 42 in the outer surface of the bushing and when the bushing is to be opened the ring 41 is rotated around in its groove until the split portion of the ring coincides with the plane of division in the bushing. This allows the bushing to be opened. When the bushing is closed, however, the ring may be slid around in its groove by inserting a pin within an opening 42 and moving the said ring in its groove until the line of division in the ring passes the plane of division in the bushing.

It is contemplated to form on the outer surface of the bushing 14, adjacent the upper end, a pair of opposed recesses 43 shaped to allow the same to be engaged by the hands of the operator. As will be seen from Fig. 5, these recesses 43 are under-cut on the upper side as well as at one lateral portion of the recess so that the fingers of the operator may engage therein so as to raise or open the bushing while it is being placed in position or removed therefrom.

The operation of this device has already been described. The inner bushing will be inserted into position by securing it about the inner pipe and dropping it into its seat. It may then be quickly locked in that position by rotating the latching ring 26, so as to throw the locking bolts 27 into the groove in the outer surface of the bushing and secure it firmly in position. If gas pressure is exerted upwardly through the casing it will tend to expand both'of the packers 16 and 37 and firmly seal the upper end of the casing and avoid danger of a blowout.

In Fig. 6 the casing head 2 is adapted to receive a single bushing 45 of somewhat heavier and different construction from that shown in the Fig. 1 embodiment. This bushing is shaped to flt the seat within the casing head and to be latched in position by the latching bolts 9 in the same manner as was the bushing 10 previously described. The outer end of the bushing 45 is recessed to receive a packing member 16' of the same construction as is the packer 16. There is a support for the lower metal ring 20' on the packing member, however, which is made up of a ring 46, adapted to be screwed within the lower end of the bushing and to have an upper shoulder 4'7 engaging the lower end of the ring 20 holdingit in position.

Toward the upper end of the bushing, lateral outlet lines 4'7, connected with the interior, are provided. These lines tend to allow escape of fluid from the interior and may also be used to force fluid outside into the interior of the casing.

The upper end of the casing is provided with a packing member 48 which comprises a ringshaped sleeve of rubber or similar material, the outer side of which is recessed at-49 to receive fluid under pressure. The upper end of the sleeve is mortised at 50 within a recess in the lower end ing a part thereof in use. A plurality of pins 52 between the outer surface of the ring 51 and the upper end of the bushing serve to prevent'rotation of one relative to the other. The ring 51 is held in position engaging the packing member by a ring 53, which has a breech lock connected with the upper end of the bushing. There are inwardly projecting lugs 54 on the ring 53, which are adapted to be inserted downwardly through slots 55 on the bushing, as shown in Fig. 7. When the ring 53 is then rotated into position out of registration with the slots 55 it will be held firmly in position.

The lower end of the packing sleeve 48 flts within a recess 56 in the inner wall of the bushing, and the passage 57 is provided through the wall of the bushing from the inner side leading up to the chamber or cavity 49 in the packing sleeve. This allows pressure fluid from the interior of the well to reach the interior of the packing sleeve to assist in expanding it inwardly against the drill stem or tubing 28.

This embodiment of the invention is provided for the purpose of allowing the interior pipe to be withdrawn from the outer pipe under pressure. When danger of a blowout occurs the bushing may be inserted over the upper section of drill stem and placed in position, above the drill stem and the drill stem may then be withdrawn from the hole. It will be noted that the packing sleeve 48 which forms a seal with the drill stem may be -of a ring 51 seated within the bushing and formcompressed by the collars upon the drill stem so as to allow the collars to pass while the drill stem is being moved upwardly through the packing member. This will permit the entire drill stem to be drawn upwardly until the drill bit comes in contact with the lower end of the bushing 45. There is under usual conditions a master valve in the casing 1 below the casing head which may then be closed so as to shut off the escape of fluid upwardly into the casing head. The bushing 45 may then be removed with the bit from the casing head which may then be equipped to flow the fluid from the well.

During the well operations, if it becomes necessary to exert additional pressure in the chamber 49 within the packing sleeve in order to form a tight seal, this may be done by pumping pressure fluid inwardly through the lines 47, or if it becomes desirable to pump mud under pressure into the well to shut down the gas pressure in the well, this may be done through the lines 4'? in an obvious manner. This embodiment of the apparatus is valuable in that it allows the drill stem to be removed under pressure, because the collars on the drill stem may pass the packer without leakage. This can not be done in the Fig. 1 embodiment without removing the inner bushing which may at times be dangerous. It is obvious that both of these embodiments of the invention may be employed alternately depending upon the conditions which are encountered in the drilling of the well.

Although this device is shown as adapted for drilling operation it will also serve in shutting off the escape of fluid around a producing well and will form a seal between the tubing and the casing head in the same manner as has been described relative to the drill stem. While there u are two embodiments of the invention disclosed it is to be understood that the invention may assume various additional forms without departing from the spirit of the invention.

Having described our invention, what we claim is:

1. A casing head having an inner downwardly tapered seat, a bushing shaped to fit therein and seal within said head about an inner pipe, said bushing being split longitudinally and hinged adjacent the upper end thereof, a latching ring lying within a mortised groove adjacent the lower end of said bushing, and divided to allow said bushing to be opened on said hinge and slidable to be moved across the plane of "division of said bushing and hold the said bushing in closed position, and means within the contour of said bushing whereby said bushing may be gripped and including operating recesses in opposed sides of said bushing.

2. A casing head having an inner seat, a bushing shaped to fit said seat and to be opened and engaged about an inner pipe, said bushing being adapted to belatched in closed position, means engaging said bushing to anchor it in said casing head, and means between the ends of said bushing to receive fluid pressure from said well and to be thereby expanded to seal about said pipe.

3. A casing head having an inner seat, a bushing shaped to fit said seat and to be opened and engaged about an inner pipe, said bushing being adapted to be latched in closed position, a packing member contacting with said pipe, a separate packing member fitting slidably against said casing head, said members having fluid receiving chambers and responsive to fluid pressure in said chambers to seal about said bushing and means whereby pressure fluid may be introduced into said packing members including passages in said bushing connected with the interior of said head.

4. A casing head, an inner pipe, a bushing fitting within said casing head and having an inner seat, means to anchor said bushing in said casing head, means to seal between said bushing and said head, an inner bushing adapted to fit said seat and engage about said pipe, means to latch said inner bushing about said pipe, and means on said inner bushing between its ends adapted to be inflated by fluid pressure from below said casing head to seal between said outer bushing and said pipe.

5. A device for sealing about a pipe within a casing head, including an outer bushing to engage within said head and form a seal therewith, a ring in the outer surface of said bushing, latch bolts responsive to the rotation of said ring to latch said bushing in said head, an inner bushing fitting between said outer bushing and said pipe, means to latch said inner bushing nonrotatably in said outer bushing, sealing means between the ends of said inner bushing to engage said pipe and said outer bushing, and passages in said bushing for pressure fluid to inflate and expand said sealing means.

6. A device for sealing about a pipe within a casing head including two interfitting bushings, the outer of said bushings having a latching engagement with said casing head, the inner of said bushings being longitudinally divided into two sections, means to latch saidsections together, including a lower ring rotatable about said bushing, and means to latch said inner bushing in sealing, non-rotatable engagement with said outer bushing and said pipe.

GRANVILLE A. HUMASON. MARGIA MANNING. 

